Telephone transmitter



(Nb Model.)

C. A. BELL.

3 Sheets-Sheet 1.

TELEPHONE TRANSMITTER.

e l H 0Padaerltgd Feb. 16, 1886.

(No Model.) v 3 Sheets-Sheet 2.

C. A..BBLL.

- TELEPHONE TRANSMITTER.

No. 336,083. Patented Feb. 16, 1886.

N Pz". Ens. Pmwumogmpmf, washing |J.cA

(No Moderl.) n 3 Sheets-Sheet 8.

0. A. BELL. l TELEPHONE TRANSMITTER. y No. 336,083. A Patented Feb. 16, 1886.

`UNITED STATES PATENT Gerlos.

CHICHESTER A. BELL, OF VASHINCrTON, DISTRICT OF COLUMBIA.

TELEPHONE-TRANSMITTER.

SIDECIFICATION forming part of Letters Patent No. 336,083, dated February 16, 1886.

Application filed April 7, 1885. SerialNo.11,4G0.

To all whoml t may concern.-

Be it known that l, CHIcnEsrER A. BELL, of Vashington, in the District of Columbia, have invented a new and useful Improvement in Telephone-Transmitters, which improvement is fully set forth in the following specification.

This invention relates more particularly to transmitters for telephone-lines in which the current-regulator or variable resistance is a sensitive jet of conducting-liquid; but it is also applicable, at least in part, to jet-translating apparatus in general. By this latter term is to be understood an apparatus for translating or transferring sonorous vibrations from one medium to another through the medium of a sensitive j et. Such apparatus forms the subjectmatter of my applications for Letters Patent filed May 1, 1884, and ohieially numbered 129,946, 129,917, and 129,948, respectively.

In the practical use ofjettranslating apparatus operating by means of a liquid it is desirable to have some means of readily procuring, whenever desired, a supply of the liquid under the requisite degree of pressure, and of reusing the liquid again and again. For this purpose, according to the present invention, upper and lower reservoirs are provided, and they are connected by pipes, so that pressure upon the liquid in the lower reservoir can force it into the upper one, and are further combined with an air-compressor for producing sufficient pressure in the lower reservoir to lift a proper quantity of liquid the required height. Suitable valves are provided for contining the compressed air, and for insuring` that the pressure ofthe same will force the liquid through the proper pipes.

The advantages of using an air-compressor to raise the liquid are, first, that air acts as a power-storing appliance,and can besuficiently compressed by a single quick movement, so as in expanding to force the liquid into the proper reservoir; and, secondly, that the compressor is removed from contact with the liquid, which, especially if aeidified, (as it would be in an electric transmitter', for the purpose of rendering it more conductive,) would be apt to corrode the material of the compressor and impair its operation. The

air-compressor preferred is a bellows with a (No model.)

collapsible bag of rubber `and a check-valve outside of said bag. To prevent the upper reservoir from being filled above a suitable height, au overow is provided for returning the excess to the lower reservoir. Preferably the arrangement is such that the liquid is expelled from and returns to the lower reservoir through the same pipe.

In jet apparatus it is further desirable to stop thejet when the apparatus is not in use. In my former applications I have shown an automatic cock for the purpose,it being closed to stop the flow of liquid to the jet-tube by the weight of the hand telephone when this is replaced on its support. In the present invention the jet-tube is arranged to be supplied through a siphon, which is provided with a movable part, which can be operated to unseal the siphon and stop the iiow. This part may be the short leg of the siphon or a Valve controlling the inlet of air into the upper part or bend of the siphon. It is connected with the telephone-support, so as to be operated in one direction by the weight of the hand-telephone and in the other by a retractile spring or weight, or it may be by the weight of the parts themselves.

In order to insure the proper working of the apparatus, the telephone-support or device for stopping the flow of the liquid is combined with a movable stop, which prevents the movement of the same until the compressor has been operated. The act of compressing the air removes the stop. In the case of a siphon, which is unsealed by placing the hand-telephone on its support, it is necessary that it should be resealed while the liquid is raised in the tubes by the pressure of the air in the lower reservoir. inasmuch as this pressure is relieved when the compressor expands, it is important to reseal the Siphon before the compressor is released. By taking the hand-telephone from its support at this time, when the stop is out of the way, the spring shifts the telephone-support,and with it the movable part of the siphon, so as to seal the Siphon while full of liquid. It', however, the hand-telephone be removed before the compressor is operated, or after it is released, the stop prevents the movement of the telephone-support until the compressor is operated, whereupon, so soon as the stop is out of IOO the way, the spring moves the telephone-support and reseals the siphon. This part ofthe invention includes more than the combination of the movable stop with a siphon, since it can also be usefully employed in other connections-as, for example, in apparatus in which an automatic stop-cock is employed to control the flow of liquid. When the -handtelephone is removed at improper times, the failure of the apparatus to operate will show that something is wrong, and the position of the telephone-support will also indicate this. An automatic lock may, however, be provided to Vprevent the removal of the hand-v telephone from its support. except when the compressor has been properly operated. Such a lock forms part of the invention.

Among other improvements or modifications which form part of the invention, is a special arrangement of devices for adjusting the positions of the jet-tube and the electrodes. The jettube is carried by a flanged holder, which can be adjusted sidewise to a limited extent and clamped by a screw-cap in the position to which it may be adjusted. rIhe electrodes arefixed in a plug which is adjustable transversely to the jet. The end of this plug is beveled. rIhe electrodes pass through a hollow in the plug, which is filled with cement and closed by a stopper.

Having now explained the principle of the invention, what is considered, on the whole, the best mode of applying the same will be described, and also some other useful modes which I have devised.

Referring to the accompanying drawings, Figures 1, 2, and 3 are respectively a front elevation, back elevation, and vertical section in a plane at right angles to those of Figs. 1 and 2 of a telephone-station apparatus embodying thel invention. Figs. 4 to 10 are detail views of the same; Fig. 11,'a partial View, in back elevation, partly in vertical section, of an apparatus embodying the invention or a part thereof in a modified form; Fig. 12, a detail-view of the saine; Fig. 13, a back view, partly in section, illustrating a third form of the invention; Figs. 14 and 15, front and back views of a station apparatus embodying the invention, or-a part thereof, in still another form; and Figs. 16 to 18, details of the same. All the apparatus shown are of my own invention.

Like letters indicate like parts on all the iig ures.

A is the case or box; B, the vibratory plate or diaphragm; G,-the lower reservoir; D, the upper reservoir; E, the jet-tube; F, the filter; G, the pipe between the filter and the jet-tube; H, the supply-pipe between the lilter and the upper. reservoir; I, the compressor or rubber bag forming part of the compressor; K, the air-pipe; L, the telephone -supnort; M, the plug in which the electrodes of the je'trans mitter are fixed, and N the ordinary'hand telephone.

Referring to Figs. 1 'to 10, the lower reservoir, C, communicates with the upper reservoir, D, directly by the pipe P and indirectly through said pipe P, the pipe Q, the filter F, and the pipe H. The pipe P reaches nearly to the bottom of the lower reservoir, passes through a hermetically-sealed joint in the top, and enters the upper reservoir by a lateral branch, 1, which terminates at the highest level to which it is desired that the liquid stand in the upper reservoir. The pipe Q extends into the top of the pipe P. (See Fig. 10.) It is slightly smaller exteriorly than the bore of pipe P, and descends below the point where the branch 1 joins the main pipe, so that the communication with the branch outlet is through the contracted space around the pipe Q. A section of soft-rubber tube, 2, fits over the ends and makes a closejoint between the two pipes, `so that they form practically one pipe in the form ofa Siphon, with a contracted outlet into the upper reservoir from the upper part or bend of the siphon. The pipes H and Q enter and terminate at the upper part of the lter F,- while the pipe G communicates with the lower part of the same. The filter is preferably made cfa rubber cylinder, (see Fig. 6,) bored out so as to leave one end in one piece with the sides, and closed at the other end by a screw-cap, 3, a soft-rubber disk, 4, being placed inside the same in order to make a close joint. kInside the cylinder are two perforated disks, 5, of hard rubber, the lower one resting upon the ring 6, of hard rubber. The space between the disks is iilled with cotton wool, or other suitable ltering material. The pipes are sealed into the upper part of the cylinder by surrounding them with cement. The pipe H is bent over at the top, so as to enter the upper reservoir. It is closed at the end by the movable cap R, which ts loosely over 'the oblique end of the pipe H, and is free to turn thereon. The object of bringing the pipes P H in at the top of the reservoir is simply to avoid making joints in the sides or bottom, which are expensive to make,and, besides,are apt to leak. The object of carrying the pipe H nearly to the bottom of the reservoir is to seal the end of the cap R by IOO the liquid in the upper reservoir, and thus avoid the necessity of making a closejoint between it and the pipe H. The Object of the cap R is to convert the pipe H into a siphon, which can be sealed and unsealed by moving said cap'. The pipe H, with its downward and upward bends, which are not essential to an operative apparatus,but are very desirable, for the reasons stated, forms the descending leg cf the siphon. The tube 7, projecting laterally from the cap R, forms the short or ascending leg ofthe same. When the cap is turned so as to raise the tube 7 out of the liquid, as shown in Figs. 2 and 3', the siphon is unsealed, and no liquid will iiow into the pipe H. W'hen, however, it is turned so asto bring the tube 7'into the position indicated in dotted lilies, the liquid is siphoned into the pipe vH, provided, of course, air is not trapped in the Cap- R or the upper bend of the pipe H.

The tube 7 is connected with the telephonesupport L by the rod 8, which slides in and is guided by a groove in the wall of case A. The lower end of the rod 8 is bent outward and passed through a hole in the inner end of the telephone support. The tube 7 is attached by a Wire, 9, or other suitable connection, to a horizontal arm at the top of rod 8. When the hand-telephone N is suspended from the outer end of the support L, the latter is in the position shown in full lines, Fig. 2, its inner end bearing against the fixed stop 14, and the tube 7 is lifted out of the liquid. \Vhen it is removed, the support turns on its center 10 int-o the position shown in dotted lines, Fig. 2, and the tube 7 drops into the liquid, as shown in dotted lines, Fig. 3, provided the stop 11 is out of the way, as shown in dotted lines, Fig. 2. This movable stop 11 is formed of a bent lever pivoted to the case, and is normally retained in the position shown in full lines, Fig. 2, by the spiral tension -spring 12, the short arm of the lever resting against the fixed stop 13. The stop 11 is removed out ofthe path of the telephone-support by depressing thelever S, which movement compresses'the bag I. The rod 15,whose lower end is bent outward aud passed through a hole in lever S, has a horizontal arm, 16, at the upper end, which strikes the short arm of stop 11 when drawn down.l The bag I, of flexible or soft rubber, rests upon the shelf 17, and has a hole in the bottom, through which the pipe K enters. Otherwise it is imperforate. This pipe has an exterior iiange at the top inside the bag, and is provided on the outside with a screw-thread, which is engaged by the nut 18. This nut bears against the under side of shelf 17, and serves to clamp the material of the bag between said flange and the upper surface of the shelf, or, as is preferable, between said fiange and a disk inserted between the bottom of the bag and the upper surface of the shelf. A tight joint around the airpipe is thus made. Inside the bag is a spiral compression-sp ring for ex panding it when released. Above it is a fiat plate or follower connected by rods 15 and 19 with the lever S. As sh o\vn,the rods are screw-threaded and provided with nuts, which engage the follower. As shown, also, the rod lf) has at the bottom a loop, which fits over the projecting end of rod 15, which end is threaded and provided with a nut for retaining the parts in place. Of course, these are details which are entirely immaterial, and can be changed at will. On a branch of the pipe K is supported the air-inlet valve 20. It is a simple checkvalve closing upward. Itis shown in detail in Fig. 4. ltis made,preferably, of hard rubber. The lower end of the air-pipe K enters the lower reservoir by a close joint. The pipe T, for returning the liquid to the reservoir C alter it has passed the jettube and electrodes, also enters the reservoir by a close joint, and is provided at the bottom with a hard-rubber check-valve, 21, closing upward.

The mode of making a tight joint between the tubes and the glass reservoir is preferably as follows: The pipes K T (see Fig. 9) are cemented into the disk 22, or they may partly be made in one piece therewith. The reservoir is cast with a screw-threaded neck, 23, which is engaged by the screw cap 24, which clamps the disk in place. A softrubber washer, 25, is interposed between a flange on the disk 22 and the top of the neck 23. The pipe P is or may be cemented into a similar disk held in place by a screwvcap and sealed by a rubber washer.

Before proceeding farther it will be well to describe the operation of lthe apparatus ex plained. \Vhen it is desired to use the tele phone, the lever S is first depressed. This movement compresses the bag I and forces the air (which is prevented from escaping by the closing of the check-valve 20) into the upper part of reservoir C. The pressure of this confined air forces theliquid through the pipe P. A part of this liquid passes through the branch pipe 1 into the upper reservoir; but the larger part passes on through the tube Q into the filter F, which it fills, and thence through the pipe H and cap R into the upper reservoir. A small part of theliquid from the filter is also delivered through the pipe G to the jet-tube E. The liquid in the lower reservoir, C, is prevented from passing up the waste-pipe T by the check-valve 21 at its lower cud. While the lever S is held down, and while in consequence the pipes P Q H, filter F, and cap R are all full of liquid, and while also the stop 11 is out of the way, the handtelephone N is removed from its support L, which immediately turns and allows the tube 7 to drop into the liquid. The siphon between the upper reservoir, D, and the filter F by way of the pipe H is now complete, and the liquid will run out of the upper reservoir as fast as necessary to supply the jet. After the siphou has been sealed by the dropping of the tu be 7 itis no longer necessary to hold down the lever S. On releasing it the bag I expands, the air-pressure in the reservoir is relieved, and air also enters through the valve 20. The relief of the air-compression in the lower reservoir allows the liquid which has collected in the pipe T to run out into the reservoir. It also allows the liquid in pipe P to descend. lf so much liquid has been forced into the upper reservoir that its limit is above 'the end of the branch pipe, the excess is sucked back into the lower reservoir. The pipe P thus acts as an overfiow. The ingress of air through the branclnafter the liquid-level in the upper reservoir has been lowered sufliciently, prevents the pipes P Q acting as a siphon and returning the liqui l into the lower reservoir. On replacing the hand-telephone on its support the weight thereof lifts the tube 7 out of the liquid in the upper reservoir and stops the iiow of liquid to thejet-tnbe. Thejet-tube E is slipped into a flanged carrier, 27, which it fits tightly enough to be retained in position IOO i y Vcasarme by friction. This carrier is confined by a screwcap, 28, which clamps the ange. The parts are arranged (see Fig. 7) so as to allow asmall sidewise adjustment to the carrier. A glass tube, 29, surrounds thejet-tnbe. Itis cemented to the cap 3() at the top and the cup 3l at the bottom of the same, and is fastened by the metal band 32 to thediaphragm B. The plugM is tapped into the side wall of the cup, and is adjustable across the jet by turning it. The inner end of the plug is beveled. The electrodes are formed by wires which are fixed in small holes in the end of the plug and terminate on the beveled surface. They pass through the hollow of the plug, which is filled with cement, 33, and then closed by the stopper 34. The outlet or waste pipe T communicates with the bottom of the cup 31. One electrode is connected by wire 35 with the binding-post36, to which one line-wire is led. The other electrode is connected through the wire 37, handtelephone N, and wire 38 with the contactspring 39. The telephone-support L is made of conducting material, and operates as a switch, being permanently connected through the spring 40 and wire 41 with the bindingpost 42, to which the other line-wire is led. The iixed stop 14 is or may be connected by thewire 43 with a binding-post, (not shown in Figs. 1 and 2, but represented in Figs. ]4 and 15,) to which the branch containing the callbell and other signaling apparatus is led.

The arrangement of contacts and circuitconnections, it may be observed, is a common one, and of course may be changed without affecting in any way the present invention.

To prevent removal of the telephone from its support, except when the lever S is depressed so as to allow the telephone-support to turn, a locking-lever, 44, is pivoted to the case and connected with the telephone-support by a link, 45, so arranged that the locking-lever is turned at a greater angular velocity than the telephone-support. When, therefore, the parts are in the position shown in dotted lines, the telephone can easily be removed; but so long as the stop 11 is interposed to prevent the telephone-support from turning the hand-telephone cannot be removed.

In operation the jet strikes the beveled end of the plug M and the liquid spreads over the same in a thin film and completes the circuit between the electrodes. The vibrations impressed upon the jet by talking to the diaphragm B (or otherwise) produce corresponding vibrations in the resistance of the circuit through corresponding undulations. As shown, the transmitter and receiver (or hand telephone) are both included in the main circuit, and this arrangement is preferred, because the internal resistance of the transmitter is very great. Distilled water acidulated with pure sulphuric acid, to renderv it conductive, (say a solution containing one volume of acid to three hunthe electrodes, and consequently' throw the battery-current in said circuit into dred volumes ofwater,) is preferably used as the jet-liquid. n

Instead of having the cap R turn upon the inclined end of the pipe H, the cap could slide` and the cap R being attached directly to the rod 8, so that it is lifted to unseal the siphon and stop the iiow whenever the hand-telephone isplaced on its support.

The object of the arrangement of pipes l? Q H in Figs. 1, 2, and 3 is to avoid the use of a check-valve to prevent the return of the liquid to the lower reservoir. By the use of such a valve a less number of pipes can be used. For example, the pipe V, provided at the bottom with a downwardly-closing check-valve, 50, delivers the liquid into the upper part of the filter 14, (see Figs. 11 and 12,) and said liquid is then forced into the upper reservoir, D, through the pipe H. An overflow-pipe, W, is provided for returning any excess of liquid to the lower reservoir.

Instead of having the ascending leg of the siphon movable for the purpose of sealing and u'nsealing the siphon when desired, a valve can be provided for admitting or excluding air from the bend of the siphon for the same purpose.

As shown in Fig. 13, the branch pipe 51 communicates with the bend in the pipe H and terminates within the cup 52, mounted on the telephone-support, and containing suflicient mercury in the bottom to seal the end of the tube when the telephone-support is in its highest position, as shown. When the telephone-support is drawn down by the weight of the hand-telephone, the end of the branch pipe 51 is exposed, and air can enter the bend and stop the siphonage.

At 53 is a check-valve, closing upward, to prevent the liquid from being forced over into the mercury-cup.

In the apparatus of Figs. 14 to 18 the telephone -support controls a valve, which is shown in detail in Fig. 17. It is placed in the jet-supply pipe G, the two parts of which are screwed into the hard-rubber block X, provided with an inlet-passage, 56, and an outlet-passage, 57, and set in the front wall of the telephone-case, being retained in place by the screw-ring 58. A disk, 59, of hard rub. ber, faced with soft rubber, 60, iits in the end of the block and closes theend of inlet-passage 56 Whenever it is forced inward. Adisk, 61, of soft rubber, is screwed over the end of the block X, being clamped firmly at the edges by the screw-ring 58. A follower, 62, bears on the outside of disk 61. by a springarm, 63, fastened at thellower end to the case A, and provided with an incline, 64, on the outside, so that when the handtelephone is placed on its support the latter,

It is carried.

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being carried over said incline, forces the follower inward and closes the valve. Vhen the hand-telephone is removed, the retractile spring turns the telephone-support and releases the valve, so that the liquid can flow through pipe G to the jet-tube. It is necessary, however, to compress the bag I by pushi ing in the rod Y before the telephone-support can turn sufficiently to release the valve, because the triangular piece 67, pivoted to the in-ner end of the telephone-support, strikes the said rod Y, except when the latter is pushed in so as to bring the contracted part 68 in the plane of its movement. The rod Y affords no hinderance to the movement of the telephone support in the opposite direction, because. when the triangular piece strikes the rod in moving upward it will turn on its pivot in order to pass. rlhe filter-supply pipe enters the upper reservoir through the bottom. The check-valve 2() is placed at the bottom of a pipe, 70, which communicates with the upper part of the reservoir D. In this pipe is an air-chamber, 7l, in the form of afleXible rubber-cloth bag. In this apparatus there is no communication with the outer air, all the joints being hermetieally sealed, and consequently all evaporation and liability of dust to enter are avoided. The jet-tube is fixed in the upper end of the tube Z by cement. 'Ihe plug M is cemented into the lower end of said tube, the waste-pipe T entering t-he side of the same at the top of the plug. waste-pi pe T a small hole is made at 7 2, to let the gases set free by the electrolysis escape intothe upper part of the reservoir C.

It is obvious that various other modifications could be made in details without departing from the spirit of the invention, and parts of the invention can be used separately.

I do not confine myself to the proportions, dimensions, and materials herein indicated, which are given simply by way of example.

Having now fully described my said invention, what I claim isl. The combination, with the jet-tube, the upper and lower reservoirs, and the air and liquid pipes, of the compressor for forcing the liquid from the lower into the upper reservoir, the hydrostatic column between the reservoirs giving the pressure required to force the liquid through said jet tube, substantially as described.

2. The combination, with the jet-tube and the upper and lower reservoirs, of the liquidpipes connecting the upper and lower reservoirs, and the compressor and air-pipe, one of said liquid-pipes being arranged to act as an overflow to return any excess of liquid to the lower reservoir when the pressure is relieved, substantially as described.

3. The combination, with the jet-tube and the upper reservoir, of ajet-supply pipe in the form of a siphon, and a movable cap or its specified equivalent for sealing and unsealing said siphon to control the flow to the jet, subitantially as described.

In the VLl. The combination, with the upper and lower reservoirs, the liquid-pipe leading from the lower reservoir, the compressor, the jettube, and the Siphon-pipe for supplying liquid to said jet-tube, of the movable cap or its specied equivalent for sealing and unsealing said siphon, and the stop removable in the act of operating said compressor, substantially as described.

5. The combination,with the reservoirs, the connecting pipe or pipes for conveying the liquid. from the lower to the upper reservoir, the compressor, the jet-tube, and the device for controlling the ilow to said jet-tube, ofthe stop for preventing the movement of said device, removable in the act of operating said compressor, substantially as described.

6. The combination, with the upper and lower reservoirs, the compressor, the pipes,

and the jet-tube, ofthe device for controlling the flow of liquid to said jet-tube, and the movable telephone support connected with said device for operating the same automatically, substantially as described.

7. The combination of the upper and lower reservoirs, the pipes, the compressor, the jettube, the device for controlling the flow to the jet-tube, the movable telephone-support, and the removable stop, substantially as described.

8. lIhe combination, with the movable telephone-support, the compressor, and the removable stop, of the lock for preventing the removal of the hand-telephone from its snpport until the latter has been shifted, substantially as described.

9. The combination, with the reservoirs, pipes, compressor, and jet-tube, of the device .for stopping the flow to the jet-tube, the telephone support, the removable stop, and the lock for retaining the telephone on its support, substantially as described.

10. The combination, with thejet-tnbe and the upper and lower reservoirs, of the compressor, the upright pipe leading from the lower reservoir and communicating with the upper reservoir through a contracted opening, and the Siphon forming a continuation of said upright tube and serving to supply the liquid to the jet-tube, substantially as described.

Il. The combinatiomfwith the jet-tube and the upper and lower reservoirs and the compressor, of the siphon for supplying the liquid to the jet-tube, and the pipe leading from the lower reservoir and communicating With the descending leg of said siphon, substantially as described.

l2. The ltcr composed of an upright cylinder filled with ltering material, in combination with the upper reservoir, the pipe descending therefrom and opening into the filter, the jet-tube, andthe pipe between the jet-tube and the filter, said pipes being sealed into the top of' said cylinder and opening into said filter, one at the top and the other, after passing through the filtering material in the cylinder, opening into the bottom thereof, substantially as described.

IZO

13. Theconibination, with the jet-tube, the upper and lower reservoirs, and the pipes, of the compressor formed of a compressible bag, and provided with a check-valve in a branch of the air-pipe outside of said bag, substantially as described.

14. The combination, with thejet-tube and its flanged carrier, of the screw-cap for retaining the jet-tube in place by clamping said ange, substantially as described,

15. The combination,with the jet-tube, of a plug having electrodes set therein and adjustable at right angles to the tube, substantially as described.

16. The screw-plug having the electrodes set therein, substantially as described.

17.' The plug having the electrodes set there- 

